The present invention relates generally to brake systems for vehicles, and more particularly to an electromechanical braking system for use in aircraft.
Various types of braking systems are known. For example, hydraulic, pneumatic and electromechanical braking systems have been developed for different applications. In the past, however, it has not been shown to employ reliably an electromechanical braking system in a vehicle such as an aircraft.
An aircraft presents a unique set of operational and safety issues. For example, uncommanded braking due to failure can be catastrophic to an aircraft during takeoff. On the other hand, it is similarly necessary to have virtually fail-proof braking available when needed (e.g., during landing).
If one or more engines fail on an aircraft, it is quite possible that there will be a complete or partial loss of electrical power. In the case of an electromechanical braking system, issues arise as to how the brakes will be actuated in an emergency landing.
In view of such shortcomings associated with conventional electromechanical braking systems, there is a strong need in the art for an electromechanical braking system which may be employed reliably even on a vehicle such as an aircraft.
An electromechanical braking system utilizes redundancy features to provide safe and reliable braking. The braking system is configured to operate on power provided by multiple power sources. Different modes of braking are available based on whether a failure has occurred in one or more power sources. Additionally, system redundancy allows for failure in one or more primary components without total loss of braking capacity. Proportional braking is provided even in an emergency braking mode.
According to one aspect of the invention, an electromechanical braking system is provided which includes at least one electromechanical brake actuator for effecting a braking torque on a wheel of a vehicle; and a plurality of brake controllers for providing drive control signals to the at least one electromechanical brake actuator in response to an input brake command signal to effect the braking torque. The plurality of brake controllers are configured to function redundantly so as to provide the drive control signals to effect the braking torque even in the event one of the plurality of brake controllers becomes inoperative.
In accordance with another aspect of the invention, an electromechanical braking system is provided which includes a plurality of brake actuators for effecting a braking torque on wheels of a vehicle; a plurality of electromechanical actuator controllers (EMACs) for providing drive control of the brake actuators in response to brake clamp force command signals; and at least one brake control unit (BSCU) for converting an input brake command signal into the brake clamp force command signals which are provided to the EMACs. At least two of the plurality of EMACs are configured to function redundantly in providing drive control to the brake actuators in response to the brake command signals.
According to still another aspect of the invention, an electromechanical braking system is provided which includes a plurality of brake actuators for effecting a braking torque on wheels of a vehicle; at least one electromechanical actuator controller (EMAC) for providing drive control of the brake actuators in response to brake clamp force command signals; and a plurality of brake control units (BSCUs) for converting an input brake command signal into the brake clamp force command signals which are provided to the at least one EMAC. At least two of the plurality of BSCUs are configured to function redundantly in providing brake clamp force command signals to the at least one EMAC in response to the input brake command signal.